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    <title>Document</title>
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    <script>
        let p = new Promise((resolve, reject) => {
            // resolve('OK');
        });

        //第一次指定回调
        p.then(value => {
            console.log(value);
        }, reason => {
            console.error(reason);
        });

        p.then(value => {
            alert(value);
        }, reason => {
            alert(reason);
        })

       

    </script>
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